Solid cross vane rotary pump



Feb. 12, 1952 REYNOLDS 2,585,406

' SOLID CROSS VANE ROTARY PUMP Filed Aug. 4, 1947 2 SHEET SSHEET l H illy 1 11? 2 I jfzgi INVENTOR.

' 1 Tia #0105 Z 7 W Ivar/vi) Feb; 12, 1952 REYNOLDS 2,585,406

SOLID CROSS VANE ROTARY PUMP' Filed Aug. 4, 1947 2 swam-4mm 2 Bmaentor Gttotneg Patented Feb. 12, 1952 SOLID CROSS VANE ROTARY PUMP Lee T. Reynolds, Denver, 0010., assignor of five per cent to Benjamin N. Tager, Los Angeles,

Calif.

Application August 4, 1947, Serial No. 765,830

housing. It is impossible, however, with the circular housing, to have both ends of each diametric blade contact the casing throughout the circumference. This is due to the fact that the eccentric position of the rotary center shortens the distance from wall to wall of the hOllSiIlg on a line intersecting the eccentric center and at right angles to the axis of eccentricity.

The principal object of this invention is to provide a pump of this type in which solid diametric vanes in an eccentric rotor will substantially contact the inner wall ofv the housingat both ends of the vanes at all angles of rotation and to provide a method for plotting the internal Walloontour of a pump of this character so as to provide a pump of the above improved characteristics.

A further object is to provide a pump of this character which willdeliver fluid at a predetermined pressure regardless of the volume demand on the discharge. I

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efiiciency. These will become more apparent from the following description. 7

In the following detailed description of the invention, reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In'the drawing: A

Fig. l is a side view of the improved eccentric, solid vane type rotary pump, with the side plate removed on the line ll ,Fig. 2;

v Fig. 2 is a cross section through the pump, taken on the line 22, Fig. 1; a

Fig. 3 is a detail view of one ofthe pump vanes;

Fig. 4 is an enlarged lay-out diagramillustrating the method for determining the inner contour of the pump housing of Fig. 1; and

Figs. 5 and 6 are still further enlarged portions of the diagram of Fig. 4. 1 1

Conventional parts of a cross vane eccentric pump are designated by numeral as follows: pump housing l5, inner wall of pump housing l6, shaft bearingll, side plate l8, intake I9, discharge 26, supporting base 2|, rotor 22, rotor vanes 23 and 24, and rotor shaft 25.

2 Claims. (Cl. 103-138) through the eccentric center H.

The vanes 23 and 24 are notched as shown at 30 so as to by-pass each other at the axis of the rotor 22, and are slidably fitted into close receiving slots in the rotor. The axis of the rotor 22 is ofiset from the axis of the housing [5 so that the rotor will contact the inner wall It at one side, as shown at 26, and will be spaced from the inner wall H5 at the other side to provide a crescent-shaped pumping chamber 21.

The difficulty in conventional pumps has been to make both ends of each vane 23 and 24 contact, or even substantially contact, the inner wall H5 at all points of rotation. If the inner wall I 6 is circular, thevanes must have a length equal to a diameter on the line 22 of Fig. 1. This diameter is less than the true vertical diameter of the circular inner wall l6, due to the approaching curvature of the inner wall.

The difference in length depends, of course, on the amount of offset or eccentricity. With vanes equal in lengthto the diameter on line 2-2 the extremities cannot touch the inner wall at both ends when the vanes are in the position of Fig. 1. This results in leakage past the vanes, reducing the efliciency of the pump.

Inorder for the' vanesto touch the walls at both extremities, it is necessary that the inner wall be ground or turned eccentrically to a slightly oval shape so as to increase its diameter at points parallel to the line 22 of Fig. 1. The point of increase in diameter and the amount of increase are determined graphically, as shown in Figs. 3, 4, and 5.

The lay-out is made by scribing a circle with a radius R3 from an original center ID, to the approximate diameter of the desired inner wall l6, as indicated by the broken line circle in Figs. 4 and 6. The circle is .thendivided into quadrants by the diameters A-B and C--D, the former diameter intersecting the point of contact 26,'be-

tween the rotor 22 andthe wall 16.

The amount of eccentricity desired in the pump is set 01f on the diameter A-B and an eccentric center I l is located. A secondary diameter E-F is scribed parallel to the vertical diameter CD The diameter A-B cuts the original center Ii andthe center of eccentricity II which corresponds to the axis of the shaft 25.

Two tangent lines 28 are drawn from points, see l2, of intersection between the diameter CD and the original broken line circle at right angles to the diameter C-D to intersect the secondary diameter EF at the points iii. The

points I3 are now used as centers and arcs 29 formed in thecover plate 18. lThe passages 23 are scribed from them on radii R! equal to the radii R3. The arcs 29, scribed from the centers IS on a radius corresponding to the radius of the original broken line circle, cut the original diameter CD at points H! on each side of the original center 10.

The points is form centers for the finish turning or grinding of the inner wall 6 oi the housing. The inner wall at one side of the diameter AB is ground concentric to the point It on that side to a radius R2 equal to the original radius R3. The wall of the housing lil-onthe other side of the diameter A-B -is. similarly ground concentric to the other poi'nt hl andto the radius R2 corresponding to the originalradius R3fiThisimparts an ovate contour to the inner wall I6, as shown in solid line at I6 in Figt l.

The vanes 23 and 24 are cut to the-length of the diameter A-B. These vanes radiate from the center H, as indicated by vane diameters G H and JK in'Fig. ,4. All of the diameters A-B, G-H, and are 'equaL'so that-both extremities of each' vane :willsubstantially contact the inner wall I 6 ofthe housing at allpoints of rotation.

Actual models having"various diameters and various amounts "of" eccentricity, have been "found to retain a' se'althroughout 360 within I The "extremities offthe'vanes 23 and-24 are a rounded to correspondtothe curvature of the inner'surface 16 attheip'oints E and F Pumps of thifcharacter increase the motor "load in proportion to'the restriction of the dis-c -charge. This'is undesirable 'in'services where the volume 'demand'bn the pump is variable.

' To accommodate: the pump to variable demand uniform pressure'services; a discharge by-pass passage 28 and an"intaketbymasspassage 29 are and 29 communicate with the intake and discharge extremities of the pumping chamber '21. The two passages communicate witheach other 'through a valve port30 controlled by means "of a pressure relief valve 3! mounted'on a valve 'stem' 32. 'The valve 3i"is'-'constantly 'urg ed over "the port 30 by means of a'compression'spring -33. The pressureagainstl the valve 31' may bepreset by a threadedspring pressure'bushing 34 "which bears 'ajgairistthe spring 33/ The valve stem 32'extendsfthrough'"the bushing 34. A threaded I stop lug 35 may "be brought into contact with the end of the valve stem 32-to hold the valve '31 permanently closed when desired. *The' bushing-'34 may be set to open at any desired' pressure,"say'500 p. s. i. Should thedischarge berestricted so that the pressure therein reaches-500 p. s. i. the excess fluid will by-pass through the valve'port 38 from the discharge side of the pump to the intake sidethereof to balance the pressure on the vanes'23 and 24 and relieve theload on the driving motor,

'Whil a'specific form of the improvement has been-described and illustrated herein, itisdesired to be understood that the same'may *be" varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, whatis wpumpingmha'inber at a predetermined point on a theoretialline extending axially "of said pumping chamber, the point of theoretical line con- "tact being disposed between said inlet and said "outlet'portsf and diametrically extending vanes slidably mounted in said rotor and having ends i adaptedto'contactthe inner wall of said pumpmg chamben' the' diameter of said pumping chamber at said'theoretical line being less than the diameter onzia second diametric line positionedat right angles to the theoretical line and intersecting the axis oftsaid housing, the arcuate sides of said pumping *chamber at the extremities of the second diametric line being each concentric 'to- 'anindividuahsecondary center, j-the individual 'secondarycentersbeing spaced'equ'ally on opposite sides bfsaid theoretical line andlying in said second dianieterfmedistance-between said' theoreticalline and each 'of--said secondary centersbeing-equal to the distance a tangent line having a-length'equal to the amount of eccentricity "of said pumpwould deviate from a' true-circle at its extremity.

2. A method-for forming an oval'contour in the inner circular wall bf arreccentric solid vane pump ofthe type-"described; comprising scribing a circle aboutt-heorig-inar center 0f'said wall on a radius substantially "equaling the-radius of said inner-wall; locatingan eccentric center spaced from said'originalcenter a distance equal to the desired-"eccentricity of said pump; drawing' a first diameter through said circle intersecting both centers; drawing asecond diameter at" right angles to the first diameter through said original center; drawing a third diameter through said eccentric center parallel to the second diameter;- drawing a "tangent line from each intersectionof the second diameter with the "original circle todntersecting-points with the third diameter; scribing arcs of radiiequal to the originalcircle-from said intersectin points to cut saidsecond diameter to locate secondary centersthereon'at each side of the first diameter;thence'removing material from said wallon a radius about each secondary "center equal to the radius of the'original' circle.

LEE TI REYNOLDS.

5 REFERENCES CITED The following references are of record-lathe file of this patent:

UNITED STATES PATENTS Number Name Date 1,196,977 1 Piatt Sept. 5, i916 l,626,5l0 Chase Apr. 26, 1927 1 ,93'81854 "'Moulet Dec. 1 2', 1933 1,974,112 Johnson Sept. 18, '1934 $032,885 Murphy Mar. 3,1936 2,046,873 Garrison July 7, 1936 235L817 Johnson June 20, 1944 2,359,903 Fanning OctnlO', 1944 

